Stool For Occult Blood

Also known as Faecal Occult Blood (FOB)

You need to provide

Stool

This test is for

Male, Female

Test Preparation

Vitamin C when taken in amounts greater than 250 mg per day has been shown to induce false negative results; Rectal medications (suppositories) and iron containing medications may also interfere with these tests and should be discontinued two days before and during the test period with the consent of the physician; For at least 2 days before and during the test period all raw meat and red meat should be avoided. Raw broccoli, cauliflower, radishes and turnips may cause false positive results, hence should be avoided.
Do not use match box or absorbant material. Patient should avoid meat products, pain killers, iron tablets, Vitamin C (Ascorbic Acid) and hard tooth brush for 3 days prior to specimen collection.

Understanding Stool For Occult Blood

What is Stool For Occult Blood?

The stool test for occult blood, also called a fecal occult blood test (FOBT) checks the presence of blood in stool that is not visible to the naked eye. Blood in the stool is indicative of some kind of bleeding in the digestive tract which could be indicative of conditions like polyps, ulcers and colorectal cancer.

The fecal occult blood test can only detect the presence or absence of blood, it can't determine what's causing bleeding. This is a simple, inexpensive, and most frequently performed stool test. An FOBT is a screening test that may help find colorectal cancer early when treatment is most effective.

If your test results are positive, additional tests such as a colonoscopy are recommended to figure out the exact location of bleeding.

What is Stool For Occult Blood used for?

To screen for digestive tract bleeding, which may be an indicator of colon cancer, asymptomatic ulcerated lesions of the GI tract, polyps, hemorrhoids, diverticulosis, and Colitis (a type of inflammatory bowel disease).
To evaluate unexpected anemia

What does Stool For Occult Blood measure?

Invisible blood (occult blood in stool) can be a screening test of carcinoma colon (a type of cancer) and can help in early diagnosis and management. Most cases of colon cancer begin with benign intestinal polyps which are relatively common in people over the age of 50. Mostly, these polyps may not cause any health problems, but some can become cancerous. These finger-like growths which extend into the intestinal cavity (lumen) or the rectum. They can be fragile and may bleed occasionally when fecal mass brushes against them. This can be detected by a fecal or stool occult blood test. This small amount of blood may be the first and sometimes the only sign of early colon cancer thereby making a stool for occult blood a valuable screening tool for colorectal (colon and rectal) cancer.

It is recommended that at least three stool samples should be collected on different days. The American Cancer Society has stated that a single test performed at the time of a digital rectal exam in a health practitioner's office is not recommended because the sample may not be sensitive enough to screen for cancer. The home FOBT or FIT is recommended because the collection of stools on three different days increases the chance of detecting cancer. Furthermore, it is recommended that those who choose this method of colon cancer screening should get screened every year.

Interpreting Stool For Occult Blood results

Interpretations

Normal result: negative means occult blood is not present in the stool.

Positive stool occult blood test means that there is bleeding somewhere in your digestive tract asymptomatic ulcerated lesions of the GI tract, polyps, hemorrhoids, diverticulosis, Colitis, and colorectal cancer. If stool for occult blood is positive, then additional tests may be required such as colonoscopy in order to detect the exact location and cause of your bleeding.

Answers to Patient Concerns & Frequently Asked Questions (FAQs) about Stool For Occult Blood

Frequently Asked Questions about Stool For Occult Blood

Q. How is stool test for occult blood done?

The method of collection and testing depends on the test procedure used and can vary from laboratory to laboratory. For the guaiac-based test, the laboratory will provide three test cards. Separate stool samples are collected on three consecutive days and for each test, a stool sample should be collected into a clean container and should not be contaminated with urine or water. A test card is labeled with the person's name and the date. A thin smear of stool is put onto a designated area on the card and allowed to dry. Once it is dry, it is stable for several weeks at room temperature. When all the consecutive samples have been collected and dried, the test cards are returned to the health practitioner or laboratory, usually by mailing them. With the OTC flushable reagent pad/tissue method, a test pad/tissue is placed in the toilet after a bowel movement. The pad contains a chemical that produces a color change when blood is present. The person doing the test watches for the characteristic color change and records the findings on a report form. Like the gFOBT, this test is usually done on three consecutive days and then the completed form is returned to the health practitioner. The use of toilet bowl cleansers or the presence of blood-derived from urine or a woman's menstrual period may alter results. With the fecal immunochemical tests (FIT), a common approach is to use a special long-handled brush or any other device in order to collect a sample from the surface of a stool sample. The brush or device is then used to transfer the sample to a special collection card. After the card is allowed to dry, it is returned to the laboratory for further analyses.

Q. Is there any preparation required before the test?

Inform the doctor about the medications you may be taking. No other specific preparations are usually required before this test.

Q. What other tests are available to screen carcinoma colon?

Other available tests to screen carcinoma colon include Sigmoidoscopy which is an endoscopic examination of the rectum and lower colon. If polyps are found, they may be removed during the procedure and examined by a pathologist to see if cancer is present. Screening with sigmoidoscopy should be done once every 5 years; Colonoscopy which is a more thorough examination of the rectum and entire colon using a flexible endoscope. If polyps are found, they may be removed during the procedure and examined by a pathologist to see if cancer is present. This procedure is recommended for screening every 10 years; CT colonoscopy (virtual colonoscopy) which uses computed tomography to visualise the entire colon. The recommended screening interval is 5 years and Double-contrast barium enema which is a series of X-rays of the colon and rectum is taken. It is recommended every 5 years.

Q. Why more than one stool sample is required?

Bleeding, especially from polyps and tumors, is periodical. Therefore, blood is not uniformly distributed in all stool samples. This means an exact interpretation of results from a single test cannot be made. Hence, taking three different samples on three different days can increase the chances of detecting occult bleeding.

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